<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>路径</title>
</head>
<body>
    <canvas id="canvas" width="600" height="600"></canvas>
    <script>
        var canvas=document.getElementById("canvas");
        var cxt=canvas.getContext("2d")
        cxt.rect(80,150,150,150)
        cxt.fill();
        cxt.beginPath();
        cxt.arc(150, 370, 60, 0, Math.PI*3/2);
        cxt.stroke();
    </script>
</body>

</html>